dcm_resize: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/dcm_resize - from package: ctn

You may install the required package with command apt-get install {package}
Error in other languages:
dcm_resize: bevel nie gevind nie
dcm_resize: comandă negăsită
dcm_resize: comando não encontrado
dcm_resize: commande introuvable
dcm_resize: command not found
dcm_resize: käsku ei ole
dcm_resize: không tìm thấy lệnh
dcm_resize: komanda nerasta
dcm_resize: Kommando nicht gefunden.
dcm_resize: kommandot finns inte
dcm_resize: komut yok
dcm_resize: nie znaleziono polecenia
dcm_resize: níor aimsíodh an t-ordú
dcm_resize: no se encontró la orden
dcm_resize: no s'ha trobat l'ordre
dcm_resize: opdracht niet gevonden
dcm_resize: parancs nem található
dcm_resize: perintah tidak ditemukan
dcm_resize: príkaz nenájdený
dcm_resize: příkaz nenalezen
dcm_resize: команда не найдена
dcm_resize: командата не е открита
dcm_resize: 命令找不到
dcm_resize: コマンドが見つかりません